Inflammatory pseudotumor of the liver. Report of four cases and review of the literature.

In this report, we describe four cases of inflammatory pseudotumor of the liver and review the literature of this disease entity. The age of our patients ranged from 31 to 35 years (mean, 33 years). Two had fever, weight loss, and upper abdominal pain. The other had an incidental 1-cm nodule in the liver found during left hemihepatectomy for recurrent attacks of cholangitis. The preoperative clinical diagnoses in the former two cases were hepatocellular carcinoma. The patients had unremarkable recovery after resection. Grossly, the tumors showed a variegated appearance with areas of hemorrhage and necrosis and resembling hepatocellular carcinoma. Microscopically, the tumors were composed of a polyclonal population of reactive plasma cells and abundant plump spindle cells. The latter expressed vimentin but stained negatively for actin, desmin, and myosin. Ultrastructurally, these plump spindle cells showed features of fibroblastic differentiation. Forty-seven cases of inflammatory pseudotumor of the liver have been reported, 35 in males and 12 in females (male-to-female ratio of 2.9). The patients had a wide age range (10 months to 83 years; mean, 37 years). The most common symptoms were fever, upper abdominal pain and a space-occupying lesion in the liver. Surgical excision was curative. A few patients responded to antibiotic and steroid treatment. The recognition and distinction of this entity from hepatocellular carcinoma and other malignant tumors is particularly important in order to avoid unnecessary extensive surgery.